[Location] With the elbow flexed and the lateral palms towards each other, on the margin of the forearm, superior to the styloid process of the radius, 1.5 cun above the transverse crease of the wrist. When the patient is asked to cross the index fingers and thumbs of the both hands with the index finger of one hand placed on the styloid process of the radius of the other hand, it can be localized in the depression exactly under the tip of the index finger. (Fig. 3 )
 
[Regional Anatomy] Skin→subcutaneous tissue→abductor pollicis longus' tendon→brachioradialis' tendon→pronator quadratus. Superficial layer, the cephalic vein, the lateral branchial cutaneous nerve, and the superficial ramus of the radial nerve; deep layer, the branches of radial artery and radial vein.